The overall objective of this research program is to study the various factors that control the various cardiovascular functions throughout intrauterine life, during the neonatal period and up until the adult state is reached. The studies encompass the following: a) ontogenetic development of the sympathetic and parasympathetic control of the circulation. This involves both In Vivo and In Vitro investigation; b) the behavior of the fetal, neonatal and adult cardiovascular functions during adrenergic depletion; c) the role of the histaminergic and dopaminergic receptors in health and disease; and d) the impact of anesthetic agents and of the neonatal changes on the cardiovascular responses to hypovolemia. BIBLIOGRAPHIC REFERENCES: Woods, J.R. Jr., Brinkman, C.R. III, Dandavino, A., Murayama, K. and Assali, N.S.: Action of histamine and H1 and H2 blockers on the cardiopulmonary circulation, Am. J. Physiol., 232/1, H73-78, 1977. Dandavino, A., Woods, J.R. Jr., Murayama, K., Brinkman, C.R. III and Assali, N.S.: Circulatory effects of magnesium sulfate in normotensive and renal hypertensive pregnant sheep, Am. J. Obstet. Gynecol., 127:769-774, 1977.